Estrogenic compounds as anti-mitotic agents

ABSTRACT

The application discloses methods of treating mammalian diseases characterized by abnormal cell mitosis by administering estradiol derivatives including those comprising colchicine or combretastatin A-4 structural motifs of the general formulae found below in a dosage sufficient to inhibit cell mitosis. The application discloses novel compounds used in the methods.

CROSS REFERENCE TO PRIOR RELATED CASES

This application is a divisional of U.S. application Ser. No. 08/838,699filed Apr. 25, 1997, now U.S. Pat. No. 5,892,069, which is a divisionalof U.S. application Ser. No. 08/571,265 filed Dec. 12, 1995, now U.S.Pat. No. 5,661,143, which is a continuation of application Ser. No.08/102,767, filed Aug. 6, 1993, now U.S. Pat. No. 5,504,074. Each of theabove-referenced applications is incorporated herein in its entirety.

BACKGROUND OF THE INVENTION

This invention relates to treating disease states characterized byabnormal cell mitosis.

Cell mitosis is a multi-step process that includes cell division andreplication (Alberts, B. et al. In The Cell, pp. 652-661 (1989); Stryer,E. Biochemistry (1988)). Mitosis is characterized by the intracellularmovement and segregation of organelles, including mitotic spindles andchromosomes. Organelle movement and segregation are facilitated by thepolymerization of the cell protein tubulin. Microtubules are formed fromα and β tubulin polymerization and the hydrolysis of guanosinetriptosphate (GTP). Microtubule formation is important for cell mitosis,cell locomotion, and the movement of highly specialized cell structuressuch as cilia and flagella.

Microtubules are extremely labile structures that are sensitive to avariety of chemically unrelated anti-mitotic drugs. For example,colchicine and nocadazole are anti-mitotic drugs that bind tubulin andinhibit tubulin polymerization (Stryer, E. Biochemistry (1988)). Whenused alone or in combination with other therapeutic drugs, colchicinemay be used to treat cancer (WO-9303729-A, published Mar. 4, 1993;J03240726-A, published Oct. 28, 1991), alter neuromuscular function,change blood pressure, increase sensitivity to compounds affectingsympathetic neuron function, depress respiration, and relieve gout(Physician's Desk Reference, Vol. 47, p. 1487, (1993)).

Estradiol and estradiol metabolites such as 2-methoxyestradiol have beenreported to inhibit cell division (Seegers, J. C. et al. J. SteroidBiochem. 32, 797-809 (1989); Lottering, M-L. et al. Cancer Res. 52,5926-5923 (1992); Spicer, L. J. and Hammond, J. M. Mol. and Cell. Endo.64, 119-126 (1989); Rao, P. N. and Engelberg, J. Exp. Cell Res. 48,71-81 (1967)). However, the activity is variable and depends on a numberof in vitro conditions. For example, estradiol inhibits cell divisionand tubulin polymerization in some in vitro settings (Spicer, L. J. andHammond, J. M. Mol. and Cell. Endo. 64, 119-126 (1989); Ravindra, R., J.Indian Sci. 64(c) (1983)), but not in others (Lottering, M-L. et al.Cancer Res. 52, 5926-5923 (1992); Ravindra, R., J. Indian Sci. 64(c)(1983)). Estradiol metabolites such as 2-methoxyestradiol will inhibitcell division in selected in vitro settings depending on whether thecell culture additive phenol red is present and to what extent cellshave been exposed to estrogen. (Seegers, J. C. et al. Joint NCI-ISTSymposium. Biology and Therapy of Breast Cancer. Sep. 25-Sep. 27, 1989,Genoa, Italy, Abstract A58).

Numerous diseases are characterized by abnormal cell mitosis. Forexample, uncontrolled cell mitosis is a hallmark of cancer. In addition,cell mitosis is important for the normal development of the embryo,formation of the corpus luteum, wound healing, inflammatory and immuneresponses, angiogenesis and angiogenesis related diseases.

SUMMARY OF THE INVENTION

I have discovered that certain compounds within the scope of the generalformulae set forth below in the claims are useful for treating mammaliandiseases characterized by undesired cell mitosis. Without wishing tobind myself to any particular theory, such compounds generally inhibitmicrotubule formation and tubulin polymerization and/ordepolymerization. Compounds within the general formulae having saidinhibiting activity are preferred. Preferred compositions may alsoexhibit a change (increase or decrease) in estrogen receptor binding,improved absorbtion, transport (e.g. through blood-brain barrier andcellular membranes), biological stability, or decreased toxicity. I havealso discovered certain compounds useful in the method., as described bythe general formulae of the claims.

A mammalian disease characterized by undesirable cell mitosis, asdefined herein, includes but is not limited to excessive or abnormalstimulation of endothelial cells (e.g., atherosclerosis), solid tumorsand tumor metastasis, benign tumors, for example, hemangiomas, acousticneuromas, neurofibromas, trachomas, and pyogenic granulomas, vascularmalfunctions, abnormal wound healing, inflammatory and immune disorders,Bechet's disease, gout or gouty arthritis, abnormal angiogenesisaccompanying: rheumatoid arthritis, psoriasis, diabetic retinopathy, andother ocular angiogenic diseases such as retinopathy of prematurity(retrolental fibroplasic), macular degeneration, corneal graftrejection, neovascular glaucoma and Osler Weber syndrome. Otherundesired angiogenesis involves normal processes including ovulation andimplantation of a blastula. Accordingly, the compositions describedabove can be used to block ovulation and implantation of a blastula orto block menstruation (induce amenorrhea).

Other features and advantages of the invention will be apparent from thefollowing description of preferred embodiments thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph illustrating the inhibition of tubulin polymerizationby 2-methoxyestradiol described by Example 1 below.

FIG. 2 is a graph illustrating the inhibition of colchicine binding totubulin by 2-methoxyestradiol described by Example 2 below.

FIG. 3 depicts: I. colchicine, 2-methoxyestradiol and combretastatinA-4, and II. various estradiol derivatives comprising colchicine (a-c)or combretastatin A-4 (d) structural motifs as described below.

COMPOUNDS ACCORDING TO THE INVENTION

As described below, compounds that are useful in accordance with theinvention include novel estradiol derivatives that bind tubulin, inhibitmicrotubule formation or exhibit anti-mitotic properties. Specificcompounds according to the invention are described below.

wherein:

I. R_(a)-R_(o) are defined as follows:

A) each R_(a), R_(b), R_(c), R_(d), R_(e), R_(f), R_(i), R_(j), R_(k),R_(L), R_(m), R_(o), independently is —R₁, —OR₁, —OCOR₁, —SR₁, —F,—NHR₂, —Br, or —I; and R_(g) is —R₁, —OR₁, —OCOR₁, —SR₁, —F, —NHR₂, —Br,—I, or —C≡CH; or

B) each R_(a), R_(b), R_(c), R_(f), R_(k), R_(L), R_(o), independentlyis —R₁, —OR₁, —OCOR₁, —SR₁, —F, —NHR₂, —Br, or —I; and each R_(d),R_(e), R_(i), R_(j), R_(m), independently is ═O, —R₁, —OR₁, —OCOR₁,—SR₁, —F, NHR₂, —Br or —I; and R_(g) is ═O, —R₁, —OR₁, —OCOR₁, —SR₁, —F,—NHR₂, —Br, —I, or —C≡CH; and

II. Z′ is defined as follows:

B)

 where R_(n) is —R₁, —OR₁, —SR₁, —F, —NHR₂, —Br or —I; and X′ is X, asdefined above; or X′ is >C═O; and

III. Z″ is defined as follows:

 where Rp is —R₁, OR₁, —SR₁, —F, —NHR₂, —Br or —I and Y is defined as inIII(A); and

IV. provided that when each R_(b), R_(c), R_(d), R_(e), R_(i), R_(j),R_(k), R_(L), R_(m) and R_(o) is H;

Rf is —CH₃;

Rg is —OH;

Z′ is >COH; and

Z″ is >CH₂;

then R_(a) is not —H;

where, in each formula set forth above, each R₁ and R₂ independently is—H, or a substituted or unsubstituted alkyl, alkenyl or alkynl group ofup 6 carbons. Those skilled in the art will appreciate that theinvention extends to other compounds within the formulae given in theclaims below, having the described characteristics. Thesecharacteristics can be determined for each test compound using theassays detailed below and elsewhere in the literature.

Without wishing to bind myself to specific mechanisms or theory, itappears that certain compounds that are known to inhibit microtubuleformation, bind tubulin and exhibit anti-mitotic properties such ascolchicine and combretastatin A-4 share certain structural similaritieswith estradiol. FIG. 3 illustrates the molecular formulae of estradiol,colchicine, combretastatin A-4, and improved estradiol derivatives thatbind tubulin, inhibit microtubule assembly and exhibit anti-mitoticproperties. Molecular formulae are drawn and oriented to emphasizestructural similarities between the ring structures of colchicine,combretastatin A-4, estradiol, and certain estradiol derivatives.Estradiol derivatives are made by incorporating colchicine orcombretastatin A-4 structural motifs into the steroidal backbone ofestradiol.

FIG. 3, part I, depicts the chemical formulae of colchicine,2-methoxyestradiol and combretastatin A-4. FIG. 3, part IIa-d,illustrates estradiol derivatives that comprise structural motifs foundin colchicine or combretastatin A-4. For example, part II a-c showsestradiol derivatives with an A and/or B ring expanded from six to sevencarbons as found in colchicine and part IId depicts an estradiolderivative with a partial B ring as found in combretastatin A-4. Each Cring of an estradiol derivative, including those shown in FIG. 3, may befully saturated as found in 2-methoxyestradiol. R₁₋₆ represent a subsetof the substitution groups found in the claims. Each R₁→R₆ canindependently be defined as —R₁, OR₁, —OCOR₁, —SR₁, —F, —NHR₂, —Br, —I,or —C≡CH.

DETAILED DESCRIPTION OF THE INVENTION

Anti-mitotic Activity in Situ

Anti-mitotic activity is evaluated in situ by testing the ability of animproved estradiol derivative to inhibit the proliferation of new bloodvessel cells (angiogenesis). A suitable assay is the chick embryochorioallantoic membrane (CAM) assay described by Crum et al. Science230:1375 (1985). See also, U.S. Pat. No. 5,001,116, hereby incorporatedby reference, which describes the CAM assay. Briefly, fertilized chickembryos are removed from their shell on day 3 or 4, and amethylcellulose disc containing the drug is implanted on thechorioallantoic membrane. The embryos are examined 48 hours later and,if a clear avascular zone appears around the methylcellulose disc, thediameter of that zone is measured. Using this assay, a 100 mg disk ofthe estradiol derivative 2-methoxyestradiol was found to inhibit cellmitosis and the growth of new blood vessels after 48 hours. This resultindicates that the anti-mitotic action of 2-methoxyestradiol can inhibitcell mitosis and angiogenesis.

Anti-Mitotic Activity in Vitro

Anti-mitotic activity can be evaluated by testing the ability of anestradiol derivative to inhibit tubulin polymerization and microtubuleassembly in vitro. Microtubule assembly is followed in a Gilfordrecording spectrophotometer (model 250 or 2400S) equipped withelectronic temperature controllers. A reaction mixture (allconcentrations refer to a final reaction volume of 0.25 μl ) contains1.0M monosodium glutamate (ph 6.6), 1.0 mg/ml (10 μM) tubulin, 1.0 mMMgCl₂, 4% (v/v) dimethylsulfoxide and 20-75 μM of a composition to betested. The 0.24 ml reaction mixtures are incubated for 15 min. at 37°C. and then chilled on ice. After addition of 10 μL 2.5 mM GTP, thereaction mixture is transferred to a cuvette at 0° C., and a baselineestablished. At time zero, the temperature controller of thespectrophotometer is set at 37° C. Microtubule assembly is evaluated byincreased turbity at 350 nm. Alternatively, inhibition of microtubuleassembly can be followed by transmission electron microscopy asdescribed in Example 2 below.

Indications

The invention can be used to treat any disease characterized by abnormalcell mitosis. Such diseases include, but are not limited to: abnormalstimulation of endothelial cells (e.g., atherosclerosis), solid tumorsand tumor metastasis, benign tumors, for example, hemangiomas, acousticneuromas, neurofibromas, trachomas, and pyogenic granulomas, vascularmalfunctions, abnormal wound healing, inflammatory and immune disorders,Bechet's disease, gout or gouty arthritis, abnormal angiogenesisaccompanying: rheumatoid arthritis, psoriasis, diabetic retinopathy, andother ocular angiogenic diseases such as retinopathy of prematurity(retrolental fibroplasic), macular degeneration, corneal graftrejection, neuroscular glacoma and Oster Webber syndrome.

Improved Estradiol Derivative Synthesis

Known compounds that are used in accordance with the invention andprecursors to novel compounds according to the invention can bepurchased, e.g., from Sigma Chemical Co., St. Louis, Steroloids andResearch Plus. Other compounds according to the invention can besynthesized according to known methods from publicly availableprecursors.

The chemical synthesis of estradiol has been described (Eder, V. et al.,Ber 109, 2948 (1976); Oppolzer, D. A. and Roberts, D. A. Helv. Chim.Acta. 63, 1703, (1980)). Synthetic methods for making seven-memberedrings in multi-cyclic compounds are known (Nakamuru, T. et al. Chem.Pharm. Bull. 10, 281 (1962); Sunagawa, G. et al. Chem. Pharm. Bull. 9,81 (1961); Van Tamelen, E. E. et al. Tetrahedran 14, 8-34 (1961); Evans,D. E. et al. JACS 103, 5813 (1981)). Those skilled in the art willappreciate that the chemical synthesis of estradiol can be modified toinclude 7-membered rings by making appropriate changes to the startingmaterials, so that ring closure yields seven-membered rings. Estradiolor estradiol derivatives can be modified to include appropriate chemicalside groups according to the invention by known chemical methods (TheMerck Index, 11th Ed., Merck & Co., Inc., Rahway, N.J. USA (1989), pp.583-584).

Administration

The compositions described above can be provided as physiologicallyacceptable formulations using known techniques, and these formulationscan be administered by standard routes. In general, the combinations maybe administered by the topical, oral, rectal or parenteral (e.g.,intravenous, subcutaneous or intramuscular) route. In addition, thecombinations may be incorporated into biodegradable polymers allowingfor sustained release, the polymers being implanted in the vicinity ofwhere delivery is desired, for example, at the site of a tumor. Thebiodegradable polymers and their use are described in detail in Brem etal., J. Neurosurg. 74:441-446 (1991).

The dosage of the composition will depend on the condition beingtreated, the particular derivative used, and other clinical factors suchas weight and condition of the patient and the route of administrationof the compound. However, for oral administration to humans, a dosage of0.01 to 100 mg/kg/day, preferably 0.01-1 mg/kg/day, is generallysufficient.

The formulations include those suitable for oral, rectal, nasal, topical(including buccal and sublingual), vaginal or parenteral (includingsubcutaneous, intramuscular, intravenous, intradermal, intraocular,intratracheal, and epidural) administration. The formulations mayconveniently be presented in unit dosage form and may be prepared byconventional pharmaceutical techniques. Such techniques include the stepof bringing into association the active ingredient and thepharmaceutical carrier(s) or excipient(s). In general, the formulationsare prepared by uniformly and intimately bringing into associate theactive ingredient with liquid carriers or finely divided solid carriersor both, and then, if necessary, shaping the product.

Formulations of the present invention suitable for oral administrationmay be presented as discrete units such as capsules, cachets or tabletseach containing a predetermined amount of the active ingredient; as apowder or granules; as a solution or a suspension in an aqueous liquidor a non-aqueous liquid; or as an oil-in-water liquid emulsion or awater-in-oil emulsion and as a bolus, etc.

A tablet may be made by compression or molding, optionally with one ormore accessory ingredients. Compressed tablets may be prepared bycompressing, in a suitable machine, the active ingredient in afree-flowing form such as a powder or granules, optionally mixed with abinder, lubricant, inert diluent, preservative, surface-active ordispersing agent. Molded tables may be made by molding, in a suitablemachine, a mixture of the powdered compound moistened with an inertliquid diluent. The tablets may optionally coated or scored and may beformulated so as to provide a slow or controlled release of the activeingredient therein.

Formulations suitable for topical administration in the mouth includelozenges comprising the ingredients in a flavored basis, usually sucroseand acacia or tragacanth; pastilles comprising the active ingredient inan inert basis such as gelatin and glycerin, or sucrose and acacia; andmouthwashes comprising the ingredient to be administered in a suitableliquid carrier.

Formulations suitable for topical administration to the skin may bepresented as ointments, creams, gels and pastes comprising theingredient to be administered in a pharmaceutical acceptable carrier. Apreferred topical delivery system is a transdermal patch containing theingredient to be administered.

Formulations for rectal administration may be presented as a suppositorywith a suitable base comprising, for example, cocoa butter or asalicylate.

Formulations suitable for nasal administration, wherein the carrier is asolid, include a coarse powder having a particle size, for example, inthe range of 20 to 500 microns which is administered in the manner inwhich snuff is taken, i.e., by rapid inhalation through the nasalpassage from a container of the powder held close up to the nose.Suitable formulations, wherein the carrier is a liquid, foradministration, as for example, a nasal spray or as nasal drops, includeaqueous or oily solutions of the active ingredient.

Formulations suitable for vaginal administration may be presented aspessaries, tampons, creams, gels, pastes, foams or spray formulationscontaining in addition to the active ingredient such as carriers as areknown in the art to be appropriate.

Formulations suitable for parenteral administration include aqueous andnon-aqueous sterile injection solutions which may contain anti-oxidants,buffers, bacteriostats and solutes which render the formulation isotonicwith the blood of the intended recipient; and aqueous and non-aqueoussterile suspensions which may include suspending agents and thickeningagents. The formulations may be presented in unit-dose or multi-dosecontainers, for example, sealed ampules and vials, and may be stored ina freeze-dried (lyophilized) conditions requiring only the addition ofthe sterile liquid carrier, for example, water for injections,immediately prior to use. Extemporaneous injection solutions andsuspensions may be prepared from sterile powders, granules and tables ofthe kind previously described.

Preferred unit dosage formulations are those containing a daily dose orunit, daily sub-dose, as herein above recited, or an appropriatefraction thereof, of the administered ingredient.

It should be understood that in addition to the ingredients,particularly mentioned above, the formulations of this invention mayinclude other agents conventional in the art having regard to the typeof formulation in question, for example, those suitable for oraladministration may include flavoring agents.

EXAMPLE 1

FIG. 1 illustrates the inhibition of tubulin polymerization by2-methoxyestradiol.

A. Each reaction mixture (all concentrations refer to the final reactionvolume of 0.25 ml) contained 1.0 M monosodium glutamate (pH 6.6), 1.0mg/ml (10 μM) tubulin, 1.0 mM MGCl₂, 4% (v/v) dimethylsulfoxide, andeither 0 (curve 1) 20 μM (curve 2), 40 μM (curve 3), or 75 μM (curve 4)2-methoxyestradiol. The 0.24 ml reaction mixtures were incubated for 15min at 37° C. and chilled on ice. After addition of 10 μl of 2.5 mM GTPthe reaction mixtures were a transferred to cuvettes held at 0° C., andbaselines were established. At time zero the temperature controller wasset at 37° C. At the times indicated by the vertical dashed lines thetemperature controller was set at the indicated temperatures.

B. Each reaction mixture contained 0.8 M monosodium glutamate (pH 6.6),1.2 mg/ml (12 μM) tubulin, 4% (v/v) dimethylsulfoxide, and either 0(curve 1), 1.0 μM (curve 2), 2.0 μM (curve 3), 3.0 μM (curve 4), or 4.0μM (curve 5) 2-methoxyestradiol. The 0.24 ml reaction mixtures wereincubated for 15 min at 26° C. and chilled on ice. After addition of 10μl of 10 mM GTP the reaction mixtures were transferred to cuvettes heldat 0° C., and baselines were established. At time zero the temperaturecontroller was set at 26° C. At the time indicated by vertical dashedline the temperature controller was set at 0° C.

EXAMPLE 2

Transmission electron microscopy (TEM) can show differences between themorphology of polymerized tubulin formed in the absence or presence of2-methoxyestradiol. After a 30 min incubation (37° C.) of reactionmixtures containing the components described in Example 1, 75 μM2-methoxyestradiol was added, and aliquots were placed on 200-meshcarbon coated copper grids and stained with 0.5% (w/v) uranyl acetate.TEM magnifications from 23,100× to 115,400× were used to visualizedifferences in tubulin morphology.

EXAMPLE 3

FIG. 2 illustrates that 2-methoxyestradiol inhibits colchicine bindingto tubulin. Reaction conditions were as described in the text, with eachreaction mixture containing 1.0 μM tubulin, 5% (v/v) dimethyl sulfoxide,5 μM [³H]colchicine, and inhibitor at the indicated concentrations.Incubation was for 10 min at 37° C. Symbols as follows: ∘,2-methoxyestradiol; •, combretastatin A-4; Δ, dihydrocombretastatin A-4.Combretastatin A-4 and dihydrocombretastatin A-4 are compounds withanti-mitotic activity similar to colchicine.

EXAMPLE 4

Table 1 illustrates the inhibitory effects on tubulin polymerization invitro exhibited by estradiol or estradiol derivatives, plantanti-mitotic compounds such as colchicine, combretastatin A-4 or otherplant compounds The method is given in Example 1.

EXAMPLE 5

Table 2 lists estrogens, estradiol or estradiol derivatives that inhibitcolchicine binding to tubulin, by the method given in Example 3.

TABLE 1 Estrogenic Compound IC₅₀ (μM ± S.D.) 2-Methoxyestradiol  1.9 ±0.2 Diethylstilbestrol  2.4 ± 0.4 2-Bromoestradiol  4.5 ± 0.62-Methoxyestrone  8.8 ± 1 17-Ethynylestradiol 10.0 ± 2 2-Fluoroestradiol27.0 ± 6 Estradiol 30.0 ± 6 Estrone >402-Methoxy-17-ethynylestradiol >40 Estriol >40 2-Methoxyestriol >40Estradiol-3-O-methyl ether >40 2-Methoxyestradiol-3-O-methyl ether >404-Methoxyestradiol >40 4-Methoxyestradiol-3-O-methyl ether >40 PlantProducts IC₅₀ (μM ± S.D.) Colchicine 0.80 ± 0.07 Podophyllotoxin 0.46 ±0.02 Combretastatin A-4 0.53 ± 0.05 Dihydrocombretastatin A-4 0.63 ±0.03

IC₅₀ values are defined as the concentration of an estradiol derivativerequired to inhibit tubulin polymerization by 50%. IC₅₀ values wereobtained in at least two independent experiments for non-inhibitoryagents (IC₅₀>40 μM) and at least three independent experiments forinhibitory compounds. IC₅₀ values were obtained graphically, and averagevalues are presented. S.D., standard deviation.

TABLE 2 Estrogenic Compound Percent inhibition ± S.D. 2-Methoxyestradiol82 ± 2 2-Methoxyestrone 57 ± 6 17-Ethynylestradiol 50 ± 7 Estradiol 38 ±4 Diethylstilbestrol 30 ± 4

Reaction conditions were described in Example 3, with each reactionmixture containing 1.0 μM tubulin, 5% (v/v) dimethyl sulfoxide, 2 μM[³H]colchicine, and 100 μM inhibitor. Incubation was for 10 min at 37°C. Average values obtained in three independent experiments arepresented in the table, except for 2-methoxyestrone, which was onlyexamined twice. S.D., standard deviation.

What is claimed is:
 1. A compound of the formula:

wherein: I. R_(a)-R_(o) are defined as follows: A) each R_(a), R_(b),R_(c), R_(d), R_(e), R_(f), R_(g), R_(h), R_(j), R_(k), R_(L), R_(m),R_(n), R_(o) independently is —R₁, —OR₁, —OCOR₁, —SR₁, —F, —NHR₂, —Br,or —I; and R_(i) is —R₁, —OR₁, —OCOR₁, —SR₁, —F, —NHR₂, —Br, —I or—C≡CH; or B) each R_(a), R_(d), R_(f), R_(j), R_(m), R_(n), R_(o)independently is —R₁, —OR₁, —OCR₁, —SR₁, —F, —NHR₂, —Br, —I; and eachR_(b), R_(c), R_(e), R_(g), R_(h), R_(k) independently is ═O, —R₁, —OR₁,—OCOR₁, —SR₁, —F, —NHR₁, —Br or —I; R_(L) independently is —R₁, —OR₁,—OCOR₁, —SR₁, —F, —NHR₁, —Br or —I; and R_(i) is ═O, —R₁, —OR₁, —OCOR₁,—SR₁, —F, —NHR₁, —Br, —I or —C≡CH; or C) each R_(a), R_(b), R_(c),R_(d), R_(f), R_(j), R_(m), R_(n), R_(o) independently is —R₁, —OR₁,—OCR₁, —SR₁, —F, —NHR₂, —Br, —I; and each R_(e), R_(g), R_(h), R_(k)independently is ═O, R₁, —OR₁, —OCOR₁, —SR₁, —F, —NHR₁, —Br or —I; R_(L)independently is —R₁, —OR₁, —OCOR₁, —SR₁, —F, —NHR₁, —Br or —I; andR_(i) is ═O, —R₁, —OR₁, —OCOR₁, —SR₁, —F, —HNR₁, —Br, —I or —C≡—CH; andII. Z is defined as follows:

 is —R₁, —OR₁, —SR₁, —F, —NHR₂, —Br or —I; and X′ is X, as definedabove; or X′ is >C═O; where, in each formula set forth above, each R₁and R₂ independently is —H, or an alkyl, alkenyl or alkynl group of upto 6 carbons; and the bond indicated by C— — —C is absent or, incombination with the C—C bond is the unit HC═CH.
 2. A compound of theformula:

wherein I. R_(a)-R_(o) are defined as follows: A) each R_(a), R_(b),R_(c), R_(e), R_(g), R_(h), R_(k), R_(L), R_(m), R_(n), R_(o)independently is —R₁, —OR₁, —OCOR₁, —SR₁, —F, —NHR₂, —Br, or —I; andR_(i) is —R₁, —OR₁, —OCOR₁, —SR₁, —F, —NHR₂, —Br, —I or —C≡CH; or B)each R_(a), R_(e), R_(L), R_(m), R_(n), R_(o) independently is —R₁,—OR₁, —OCOR₁, —SR₁, F, —R₂, —Br, —I; and each R_(b), R_(c), R_(g), R_(h)is ═O, —R₁, —OR₁, —OCOR₁, —SR₁, —F, —NHR₁, —Br or —I; and R_(i) is ═O,—R₁, —OR₁, —OCOR₁, —SR₁, —F, —NHR₁, —Br, —I or —C≡CH; or C) each R_(a),R_(b), R_(c), R_(e), R_(k), R_(m), R_(n), R_(o) independently is —R₁,—OR₁, —OCOR₁, —SR₁, —F, —NHR₂, —Br, —I; and each R_(g), R_(h)independently is ═O, —R₁, —OR₁, —OCOR₁, —SR₁, —F, —NHR₁, —Br or —I; andR₁ is ═O, —R₁, —OR₁, —OCOR₁, —SR₁, —F, —NHR₁, —Br, —I or —C≡CH; and II.Z is defined as follows:

 is —R₁, —OR₁, —SR₁, —F, —NHR₂, —Br or —I, and X′ is X, as definedabove; or X′ is ═O; where, in each formula set forth above, each R₁ andR₂ independently is —H, or an alkyl, alkenyl or alkynl group of up to 6carbons; and the bond indicated by C— — —C is absent or, in combinationwith the C—C bond is the unit HC═CH.
 3. The compound of claim 1, whereinZ is


4. The compound of claim 2, wherein Z is


5. The compound of claim 1, wherein at least one of R_(a) to R_(o) is—OCH₃.
 6. The compound of claim 2, wherein at least one of R_(a) toR_(o) is —OCH₃.